Molecular self-assembly processes

A logical and stepwise approach to the establishment of the concept of self-assembly in the synthesis of wholly unnatural products is proposed. The approach is based on the use of irreversibly interlocked molecular systems in the shape of catenanes and rotaxanes as the vehicles through which to transfer from host-guest chemistry the knowledge and experience gained on relatively small molecules to much larger molecules including polymers in which the molecular components are reversibly intertwined. The proposal presents a manifesto for making the transformation from supramolecular to polymolecular chemistry. A number of recent template-directed syntheses of catenanes and rotaxanes are presented as examples of structure-directed synthesis, to illustrate that there are inherently simple ways of making apparently complex unnatural products from appropriate substrates without the need for reagent control or catalysis.